Hi and welcome. Please stop dosing yourself with malachite green as it is carcinogenic so you will soon have more than stress to worry about! You may also end up looking like the Incredible Hulkess, or Hulkette.
Read about the whitespot cycle and see when it is actually infectious. Just because the spots have disappeared on the fish does not necessarily mean it is gone. The cysts drop off the fish into the substrate and the meds only work at a certain time (mind has gone blank so I can't advise which part without looking it up myself).
Whitespot is certainly caused by stress and the bullying could have been the reason but it would pay to check the ammonia and nitrite levels as you say the tanks are new-ish. These should be 0.
Mr G is showing everyone whose boss. If you have a lot of plants and places for Mrs G to hide from him, he might settle down.